Identification media are known for various applications, e.g., as access cards for specific areas of a company (electronic code), for time management, as access media for the use of equipment, e.g., data systems, and also as credit/debit card systems for procuring services. For each independent application an independent medium is required, e.g., in the form of a card or an electronic code. A new application which a user wishes to implement requires an additional new medium. Thus, a user wishing to use various applications must carry a corresponding number of individual media. This is both costly and cumbersome and there is also a risk of losing or forgetting one of the numerous media or cards and then not to have it available when required.